U.S. Pat. No. 2,677,698 describes a process for the preparation of N-monosubstituted carbamic acid esters by reacting a primary amine with urea to prepare a 1,3-disubstituted urea which is separated from unreacted amine, urea and generated ammonia and then reacted in a second step with a mono-hydroxy alcohol to give the resultant N-monosubstituted carbamic acid ester.
U.S. Pat. No. 2,409,712 related to the pyrolysis of N-alkyl carbamic alkyl esters discloses a method for the preparation of such carbamic esters by reacting urea, an amine such as laurylamine or beta (isobutoxymethoxy)ethylamine and alcohols such as ethoxyethoxyethanol to give the N-alkyl carbamic alkyl esters.
The carbamates of this invention may be employed in a number of commercial applications, for example, as agricultural chemicals and as chemical intermediates which may be converted to the corresponding isocyanate and alcohol by thermal decomposition or other methods described in the prior art.